Charles w



C. W. KDHLERAND F. H. MARTIN.

GAS MASK.

APPLlcATmN FILED 1111111.18. 1918.

1.315.515. Pat-911191199111. 9,1919.4

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TED srrAtrEs PATENT. oEE'IoE.

CHARLES W. .'KOHELEIR AND FREDERICK H. MARTIN, 0F AKRON, OHIO, ASSIGN'ORS T0 THE B. l. GOODRICH COMPANY, 0F NEW YORK, NQY., A CORPORATION OF NEW YORK.

GAS-MASK.

Specification of LettersV katent.

Patented Sept. t), 1919.

Application led March 1.8, 1918. Serial No. 223,117.

To all whom it may concern:

Be it known that we, CHARLES W. Kon Lan and 'FREDERICK lfl. MARTIN, citizens of the United States, residing ats-Akron, `in the county of Summit and State of0hio, have invented a certain new and useful Gas- Maslgof which the following is a specifica tion. l

This invention relates to gas masks of the type used in warfare, andy its object is to furnish a light and flexible face-covering which shall be both waterproof and gasproof.

IThe accompanying drawin is a Side elevation, partly broken away, 1 lustrating the construction of our improved mask.

The waterproofing alone is a comparatively simple matter and may be accomplished in known ways by usingl thin sheets of vulcanized rubber or fabriccoated with rubber or'with oils or waxes or combinations of these materials. Proong against the passage of the extremely penetratingv and poisonous` gases used in modern Warfare, such as phosgen, x lyl bromid, chlor picrin and others'is muc more difficult and has neverbeen adequately'accomplished prior to our invention, so far as We are aware. Thin rubber sheets or coatings are pemneable by these gases. A fairly lthick sheet of rubber will resist for a time but is open to the 'objection that it becomes saturated with'the gas and afterward requires several hours exposure in a gas-free atmosphere in order to clear itself. 'lts thickness also diminishes r1 coating composed of glue, glycerin and water` acts very e'ectively as a gas-proofing means solong as it is kept pliable and nonporous, but is subject to the disadvantage of eing soluble in water unless hardened or set in some way, as by means of formaldehyde. 1t has been proposed to use suchv a set or insoluble coating on a rubber or fab-Y4 ric foundation, but our experlencehas beenr that they coating, while sufficiently pliable when fresh, soon dries out and then cracks, chips or peels ed so as to become oflittle use forA its intended purpose. We are not aware of any single material or composition, usa-4 ble in sheet form or as a coating, which is both waterproof and adouuatelly -proof under conditions of warfare and at the same time permanently' Horrible.

tt We hare found, however, that the desired -ter-,proof sheet, film or coating an results may be obtained by providindg Ically, we employaplurality of thicknesses of flexible materlal composed of or coated with rubber or other suitable waterproof sub stance on nthe two exposed surfaces, and havlng one or more interior sheets, coating, webs or films of a' soluble gas-proof material such as the glue, glycerln and water mixture above mentioned, these thicknesses being preferably unconnected or free from each other except at the margins of the mask and at the edges where the eye-pieces and breath? ing attachments are connected, so as to se- 4 eure the maximum degree of flexibility and other advantages. It is desirable to waterproof both the outer surface of the mask to exclude rain and snow, and its inner surface to prevent absorption .of saliva and breath moisture.

Referring to the drawing, 1 is algas mask having a flexible face-covering 2 provided with the usual eye-pieces 3, breathin fixture 4 and headstraps 5. As here sown. the body of the face-covering is composed of three plies or thicknesses of material, 6, 7, and 8, which are separate and free from each other except at the margins and around the eye-pieces `and breathing fixture. This semifreedom ofy the jplies provides greater flexibility than if they were cemented together. llt enables the mast to be crumpled or folded with no liability of cracking, permits the eye-pieces to be wiped free of :moisture on the inside by doubling the coverin in back of the windows without removing t e mask,

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ply 7 is preferably also made of woven fab ric, ver light in texture, vand is coated with a solub e gas-proof material. For example, 100 parts by welght of animal glue is soaied for 2st hours in 100 parts of cold water andl thenl heated to about 90 C. until dissolved,

after which 125 parts of glycerin is added.. A.

and the mixture thoroughly stirred. small quantity of bichlor1d of mercury or other preservative may be added to prevent putrefaction. The liquid is then applied to the cloth in successive coats by any suitable spreading method until the desired thickness is obtained, and when dry, the coated fabric is ready for use. For the glue, other forms of gelatin, or casein, may be substituted and various other modifications made without departing from our invention.

We wish it understood that we may employ any equivalent fer the particular gas` proofing and waterproofing elements here l described, since our invention lies broadly in the idea of mechanically combining one or more waterprooin and one or more gasproofing surfaces, we s, films, plies or coating substantially in the manner and for the purpose described, or for any analogous purpose, as well as in the nature ofthe gas-proofing means employed.

AWe claim: l

l. A gas-mask comprising a face covering provided with suitable eye-pieces and a breathing connection, said covering including va waterproof ply or thickness and a soluble gas-proof ply or thickness consisting of a substantially permanently flexible cumposition of glue and glycerin.

2. A flexible structure suitable for the face-covering of a gas mask, said structure around said eye-pieces and brathin 4. A gas-mask comprising a flexible facecovering having eye-pieces and a breathing fixture, said coverin plurality of plies o material with their edges brought together at the margins and xture, and their intermediate portions d1sconnected, the covering being water roofed on the outermost and innermost sur aces of the mask, and having, between the waterproofed surfaces, a soluble gas-proof surface of the nature of glue-.glycerin mixture.

5. A flexible structure suitable for the face-covering of a gas-mask, said structure comprising two waterproof plies of material, and an interposed third ply consisting of a s heet of cloth coated with gas-proof material.

6. A flexible structure suitable for the face-covering of a gas-mask, said structure comprising two waterproof plies of material, and an interposed third ply consisting of a sheet of cloth coated with soluble glue-glycerin mixture, parts of said three plies being connected to each other and other parts free.

7. A gas-mask comprising visual and breathing devices and a flexible face-covering connected therewith, said covering comprising two waterproof plies of material, and an interposed third ply provided with a soluble gas-proof surface and mainly free from said waterproof plies.

8. A gas-mask comprising visual and breathing devices and a flexible face covering connected therewith, said covering comprising two plies of rubberized fabr1c, and an interposed third ply of fabric coated with soluble glue-glycerin mixture and free from sa1d rubberized pl1es on the portions thereof around the visual and breathing dcvices and within the margins of the face covering.

In testimony whereof we have hereunto set our hands this 15th day of March 1918.

CHARLES W. KOHLER. FREDERICK H. MARTIN.

being formed ofl a 

